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*
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*
* The above copyright notice and this permission notice shall be included in
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*
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package org.luaj.vm2.lib.jse;
import java.io.File;
import java.io.IOException;
import org.luaj.vm2.Globals;
import org.luaj.vm2.LuaValue;
import org.luaj.vm2.Varargs;
import org.luaj.vm2.lib.LibFunction;
import org.luaj.vm2.lib.OsLib;
/**
* Subclass of {@link LibFunction} which implements the standard lua {@code os} library.
*
* This contains more complete implementations of the following functions
* using features that are specific to JSE:
*
* - {@code execute()}
* - {@code remove()}
* - {@code rename()}
* - {@code tmpname()}
*
*
* Because the nature of the {@code os} library is to encapsulate
* os-specific features, the behavior of these functions varies considerably
* from their counterparts in the C platform.
*
* Typically, this library is included as part of a call to
* {@link org.luaj.vm2.lib.jse.JsePlatform#standardGlobals()}
*
{@code
* Globals globals = JsePlatform.standardGlobals();
* System.out.println( globals.get("os").get("time").call() );
* }
*
* For special cases where the smallest possible footprint is desired,
* a minimal set of libraries could be loaded
* directly via {@link Globals#load(LuaValue)} using code such as:
*
{@code
* Globals globals = new Globals();
* globals.load(new JseBaseLib());
* globals.load(new PackageLib());
* globals.load(new JseOsLib());
* System.out.println( globals.get("os").get("time").call() );
* }
* However, other libraries such as MathLib are not loaded in this case.
*
* @see LibFunction
* @see OsLib
* @see org.luaj.vm2.lib.jse.JsePlatform
* @see org.luaj.vm2.lib.jme.JmePlatform
* @see Lua 5.2 OS Lib Reference
*/
public class JseOsLib extends org.luaj.vm2.lib.OsLib {
/** return code indicating the execute() threw an I/O exception */
public static int EXEC_IOEXCEPTION = 1;
/** return code indicating the execute() was interrupted */
public static int EXEC_INTERRUPTED = -2;
/** return code indicating the execute() threw an unknown exception */
public static int EXEC_ERROR = -3;
/** public constructor */
public JseOsLib() {
}
protected String getenv(String varname) {
String s = System.getenv(varname);
return s != null? s : System.getProperty(varname);
}
protected Varargs execute(String command) {
int exitValue;
try {
exitValue = new JseProcess(command, null, globals.STDOUT, globals.STDERR).waitFor();
} catch (IOException ioe) {
exitValue = EXEC_IOEXCEPTION;
} catch (InterruptedException e) {
exitValue = EXEC_INTERRUPTED;
} catch (Throwable t) {
exitValue = EXEC_ERROR;
}
if (exitValue == 0)
return varargsOf(TRUE, valueOf("exit"), ZERO);
return varargsOf(NIL, valueOf("signal"), valueOf(exitValue));
}
protected void remove(String filename) throws IOException {
File f = new File(filename);
if ( ! f.exists() )
throw new IOException("No such file or directory");
if ( ! f.delete() )
throw new IOException("Failed to delete");
}
protected void rename(String oldname, String newname) throws IOException {
File f = new File(oldname);
if ( ! f.exists() )
throw new IOException("No such file or directory");
if ( ! f.renameTo(new File(newname)) )
throw new IOException("Failed to delete");
}
protected String tmpname() {
try {
java.io.File f = java.io.File.createTempFile(TMP_PREFIX ,TMP_SUFFIX);
return f.getName();
} catch ( IOException ioe ) {
return super.tmpname();
}
}
}